Magnetic work body and magnetic heat pump device using same

ABSTRACT

A plurality of tubular bodies 30 formed of a magnetic work substance and having a porosity adjusting hole 30a adjusting the porosity when a plurality of rod-shaped bodies are made adjacent to each other and joined in an axial direction of the rod-shaped body are joined so that the cross-sectional shapes of gaps 31 surrounded by the adjacent tubular bodies have the same shape and heat medium passages passing a heat medium are formed with the inner surfaces of the tubular bodies and the gaps 31.

TECHNICAL FIELD

The present invention relates to a magnetic work body having a magnetocaloric effect and a magnetic heat pump device using the same.

BACKGROUND ART

In place of a conventional vapor compression refrigerator using a gas medium, such as chlorofluorocarbon, a magnetic heat pump device utilizing a magnetocaloric effect which is a property that a magnetic work substance causes a large temperature change in magnetization and demagnetization has recently drawn attention.

The magnetic heat pump device is configured so that the magnetic work substance is disposed in a liquid medium flow passage to exchange heat with a heat medium by the magnetocaloric effect. Conventionally, the magnetic work substance is molded into a granular shape, the granular-shaped magnetic work substances are stored in a tubular case, and a liquid medium is circulated in the tubular case.

Thus, when the magnetic work substance is molded into a granular shape, while the contact surface area with the liquid medium can be increased, the flow passage resistance of the heat medium increases, which has posed a problem that efficient heat exchange cannot be performed.

Therefore, in order to reduce the flow passage resistance of the heat medium, magnetic work bodies described in PTLS 1 and 2 have been proposed.

In PTL 1, the magnetic work substance is molded into a rectangular parallelepiped shape and a large number of through-holes are formed in the axial direction in the rectangular parallelepiped with a punch having a prong.

In PTL 2, the magnetic work substance is formed into a columnar body having a cross-sectional shape of a circular shape, an octagon shape, a cross shape, or the like, and then two or more of the columnar bodies are stored in a cylindrical case or a square tube case to forma heat medium passage between the columnar bodies.

CITATION LIST Patent Literature

PTL 1: JP 2008-527301 A

PTL 2: JP 2013-64588 A

SUMMARY OF INVENTION Technical Problem

However, the magnetic work body described in PTL 1 described above has an unsolved problem that, since a large number of through-holes are formed in the rectangular parallelepiped formed of the magnetic work substance, wastes of the magnetic work substance are generated and it is difficult to accurately form the through-holes.

Meanwhile, the magnetic work body described in PTL 2 described above has unsolved problems that a large number of the columnar bodies formed of the magnetic work substance are made adjacent to each other and space surrounded by the outer peripheral surfaces of the columnar bodies is used as a heat medium passage, and therefore, when the cross-sectional shape of the columnar body is formed into a circular shape or an octagon shape, the porosity of the space serving as the heat medium passage decreases, the flow amount of the heat medium decreases, and, in order to obtain a large flow amount, the cross-sectional shape of the magnetic work body needs to increase.

Thus, the present invention has been made focusing on the unsolved problems of the conventional examples described in PTLS 1 and 2. It is an object of the present invention to provide a magnetic work body capable of increasing the porosity to improve the heat exchange efficiency and a magnetic heat pump device using the same.

Solution to Problem

In order to achieve the above-described object, one aspect of a magnetic work body according to the present invention contains tubular bodies formed of a magnetic work substance and having a porosity adjusting hole in the axial direction configured to adjust the porosity when a plurality of penetrating rod-shaped bodies are made adjacent to each other and joined inside the rod-shaped body.

One aspect of a magnetic heat pump device according to the present invention is provided with ducts in which the above-described magnetic work bodies are disposed along a heat medium flowing direction, a magnetic field changing mechanism configured to change the magnitude of a magnetic field applied to the magnetic work body of the duct, a heat medium moving mechanism configured to move the heat medium between a high temperature end and a low temperature end of the magnetic work body, a heat dissipation side heat exchanger configured to cause the heat medium on the high temperature end side to dissipate heat, and a heat absorption side heat exchanger configured to cause the heat medium on the low temperature end side to adsorb heat.

Advantageous Effects of Invention

According to one aspect of the present invention, the magnetic work body is formed into the tubular body having the porosity adjusting hole penetrating in the axial direction and configured to adjust the porosity when the plurality of rod-shaped bodies are made adjacent to each other and joined, and therefore the magnetic work body can be configured in which a heat medium passage can be formed by a void formed of the adjacent tubular bodies and the porosity adjusting hole and the porosity can be arbitrarily adjusted by changing the inner diameter of the porosity adjusting hole.

Therefore, when the plurality of tubular bodies are made adjacent to each other to configure the magnetic work body, it becomes possible to change the porosity without changing the outer diameter of the magnetic work body.

Moreover, the magnetic heat pump device can be provided in which, by disposing the magnetic work body optimizing the porosity in the duct in which the heat medium flows, the porosity and the flow passage resistance of the heat medium can be optimally adjusted to improve the heat exchange efficiency.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is the entire block diagram illustrating one embodiment of a magnetic heat pump device according to the present invention;

FIG. 2 is a cross-sectional view of a heat pump body of FIG. 1;

FIG. 3 is a perspective view illustrating a first embodiment of magnetic work bodies;

FIG. 4 is a perspective view illustrating a single magnetic work body;

FIG. 5 is a characteristic diagram illustrating the relationship between the temperature of a magnetic work substance and an entropy change;

FIG. 6 is a view explaining the assembling error range of tubular bodies;

FIG. 7 is a characteristic diagram illustrating the temperatures of a high temperature end and a low temperature end of the magnetic work body in a state where a temperature change is saturated;

FIGS. 8A and 8B are explanatory views illustrating a method for manufacturing magnetic work bodies installed in the heat pump body;

FIG. 9 is a perspective view illustrating a second embodiment of the magnetic work body;

FIG. 10 is an enlarged view of a principal portion of FIG. 9;

FIG. 11 is a perspective view illustrating another example of a heat pump body; and

FIG. 12 is a perspective view illustrating a still another example of a heat pump body.

DESCRIPTION OF EMBODIMENTS

Next, one embodiment of the present invention is described with reference to the drawings. In the following description of the drawings, the same or similar portions are designated by the same or similar reference numerals. However, it should be noted that the drawings are schematic and the relationship between the thickness and the plane dimension, the ratio in thickness of each layer, and the like are different from actual relationship, ratio, and the like. Therefore, specific thickness and dimension should be determined considering the following description. It is a matter of course that the drawings also include portions having dimensional relationships and ratios different from each other.

Moreover, the embodiments described below illustrate devices or methods for embodying the technological idea of the present invention and the technological idea of the present invention does not specify materials, shapes, structures, arrangement, and the like of constituent components to the materials, shapes, structures, arrangement, and the like described below. The technological idea of the present invention can be variously altered in the technological scope specified by Claims described in Claims.

First, one embodiment of a magnetic heat pump device illustrating a first aspect of the present invention is described.

[Configuration of Magnetic Heat Pump Device]

A magnetic heat pump device 10 is provided with a heat pump body 11, a high temperature side switching valve 12, a heat dissipation side heat exchanger 13, a heater 14, a circulating pump 15, a low temperature side switching valve 16, and a heat absorption side heat exchanger 17 as illustrated in FIG. 1.

The heat pump body 11 configures a heat pump AMR (Active Magnetic Regenerator). The heat pump body 11 is provided with a rotor 21 coupled to a servomotor which is not illustrated through a decelerator and rotationally driven in one direction and a stator 22 as a cylindrical fixing portion containing a cylindrical case body surrounding the circumference of the rotor 21 as illustrated in FIG. 2.

The rotor 21 is provided with a rectangular parallelepiped-shaped support member 24 fixed to a rotation shaft 23 and extending in the axial direction and a pair of permanent magnets 25A and 25B serving as magnetic field generating members fixed onto the long sides facing each other of the support member 24 and extending in the radial direction and the axial direction. The permanent magnets 25A and 25B each have a wide shape and the tip on the outer peripheral side is formed into a cylindrical shape centering on the center of the rotation shaft 23.

On the inner peripheral surface of the stator 22, four hollow ducts 26A, 26B, 26C, and 26D in total, two hollow ducts of which face each other across the center at the top and bottom positions and the right and left positions, for example, are disposed at intervals of 90° in the circumferential direction extending in the axial direction of the stator 22 so as to face the outer peripheral surfaces of the permanent magnets 25A and 25B. The hollow ducts 26A to 26D each are formed of a high heat insulating resin material. This reduces heat loss to the outside of a magnetic work body having a magnetocaloric effect described later and prevents heat transfer to the rotation shaft 23 side.

The hollow ducts 26A to 26D each are formed into a flat circular-arc oblong shape by an inner cylindrical surface 26 a centering on the center of the rotation shaft 23, an outer cylindrical surface 26 b centering on the center of the rotation shaft 23, and circular-arc-shaped side surface portions 26 c and 26 d individually coupling both end portions of the inner cylindrical surface 26 a and the outer cylindrical surface 26 b and the length in the circumferential direction is selected to be substantially equal to the lengths in the circumferential direction of the permanent magnets 25A and 25B.

In the hollow ducts 26A to 26D, magnetic work bodies 27A to 27D exhibiting the magnetocaloric effect which is a property of causing a large temperature change in magnetization and demagnetization are disposed.

The magnetic work bodies 27A to 27D each are configured by joining tubular bodies 30 each serving as a single magnetic work body, which is formed of a magnetic work substance exhibiting the magnetocaloric effect and in which a porosity adjusting hole 30 a in the axial direction adjusting the porosity when a plurality of rod-shaped bodies are made adjacent to each other and joined is formed inside the rod-shaped body, in the lattice shape with a plurality of outer peripheral surfaces as illustrated in FIG. 3.

Herein, the tubular body 30 contains an extrusion-molded article manufactured by filling an extrusion molding machine with a slurry-like magnetic work substance, and then performing extrusion molding and is formed into a cylindrical body having an outer diameter of 1 mm, an inner diameter of 0.485 mm, and a length of 100 mm, for example. The tubular body 30 serving as the single magnetic work body is not limited to the cylindrical body and can contain an oval cylindrical body, a right 4 n-sided tubular body (n is 2 or more), or the like. In short, the tubular body 30 may be one in which, when two or more of the single magnetic work bodies are made adjacent to each other and joined in a direction orthogonal to the axial direction, gaps 31 surrounded by the adjacent single magnetic work bodies have a uniform shape. The shape of the porosity adjusting hole 30 a can be formed into an arbitrary shape.

Moreover, the tubular body 30 is preferably configured by arranging two or more of the magnetic work substances, e.g., three magnetic work substances of a first magnetic work substance MM1, a second magnetic work substance MM2, and a third magnetic work substance MM3, different in a temperature zone where a high magnetocaloric effect is exhibited in the axial direction so that the temperature zone becomes higher in order, for example, as illustrated in FIG. 4. As one example, those in which the relationships between a temperature T and an entropy change (−ΔS) [J/kg·K] are illustrated in FIG. 5 are selected as the three magnetic work substances MM1 to MM3.

More specifically, for the first magnetic work substance MM1, an Mn-based material or a La-based material having a chevron-shaped characteristic in which the entropy change (−ΔS) reaches the peak at a temperature Tp1 around the lowest Curie point as illustrated by a characteristic curve L1 is used. For the second magnetic work substance MM2, an Mn-based material or a La-based material having a chevron-shaped characteristic in which the entropy change (−ΔS) reaches the peak at a temperature Tp2 around the Curie point higher than that of the first magnetic work substance MM1 as illustrated by a characteristic curve L2 of FIG. 5 is used. For the third magnetic work substance MM3, an Mn-based material or a La-based material having a chevron-shaped characteristic in which the entropy change (−ΔS) reaches the peak at a temperature Tp3 around the Curie point higher than that of the second magnetic work substance MM2 is used.

The Mn-based material or the La-based material has a larger magnetic entropy change (−ΔS) by magnetization/demagnetization and also higher heat absorption/heat dissipation capacity as compared with those of a conventionally used Gd-based material. However, an operation temperature zone (driving temperature span) where the high magnetocaloric effect of each material is exhibited is narrower than that of the Gd-based material. Therefore, when used alone, the temperature cannot be changed from normal temperature to a required freezing/heat dissipation temperature (hot-water supply or the like).

Therefore, by disposing the first magnetic work substance MM1, the second magnetic work substance MM2, and the third magnetic work substance MM3 side by side in the axial direction of the tubular body 30, a high magnetocaloric effect can be obtained in a required temperature range.

Then, four tubular bodies 30 having the above-described configuration, e.g., two tubular bodies 30 on the lower side and two tubular bodies 30 on the upper side, are joined so that grid lines L11 indicated by the solid line connecting the centers of the tubular bodies 30 form a square, whereby a diamond-shaped gap 31 surrounded by the four tubular bodies 30 illustrated in FIG. 3 is formed as illustrated in FIG. 6. For the joining of the tubular bodies 30 in this case, the tubular bodies 30 are joined by a joining method, such as blazing, when joined after forming the tubular bodies 30.

The tubular bodies 30 are arranged so that allowable grid lines L12 and L13 indicated by the dotted lines setting a ±10% allowable level to the standard grid lines L11 indicated by the solid lines connecting the centers of the four tubular bodies 30 are set, and then the center is disposed in a hatched square region 32 surrounded by the intersections of the allowable grid lines L12 and L13 as illustrated in FIG. 6. By arranging the tubular bodies 30 as described above, desired porosity can be secured.

For example, ideal porosity is assumed to be 0.4. In order to secure the ideal porosity of 0.4, when the outer diameter is defined as D₁ and the inner diameter is defined as D₂ assuming that the tubular body 30 is a cylindrical body, a ratio between the diameters D₁:D₂=1:0.485 is set, whereby the porosity of 0.4 can be secured.

More specifically, when a square circumscribing the tubular body 30 is considered, the void around the tubular body 30 is expressed by (D₁ ²−πD₁ ²/4). A value obtained by adding a void πD₂ ²/4 inside the tubular body 30 thereto may be equal to 0.4D₁ ².

Therefore, by substituting D₁=1 into an equation expressed by (D₁ ²−πD₁ ²/4)+πD₂ ²/4=0.4D₁ ² and solving the equation, D₂=0.485 is given.

Thus, in order to obtain the ideal porosity of 0.4, the relationship between the outer diameter D₁ and the inner diameter D₂ of the tubular body 30 is set to 1:0.485. However, this embodiment is not limited thereto and it is preferable to set the inner diameter D₂ of the tubular body 30 in the range of 0.485×0.9 to 0.485×1.1. Herein, when the inner diameter D₂ of the tubular body 30 is less than 0.485×0.9, the flow amount of a heat medium passing through the magnetic work body decreases, so that the heat exchange efficiency decreases. When the inner diameter D₂ exceeds 0.485×1.1, the flow amount of a heat medium passing through the magnetic work body excessively increases, so that the heat exchange efficiency decreases.

In order to configure a block-shaped magnetic work body 33 illustrated in FIG. 3, the integrally molded block-shaped magnetic work body 33 can be configured by simultaneously extrusion-molding a desired number of the magnetic work bodies with an extrusion-molding machine without being limited to joining a required number of the tubular bodies 30.

Furthermore, when the magnetic work bodies 27A to 27D are accommodated in the hollow ducts 26A to 26D, respectively, described above, it takes so much time and effort to join the tubular bodies 30 while inserting the tubular bodies 30 one by one into the hollow ducts 26A to 26D because the shape of the hollow ducts 26A to 26D is a circular-arc shape and a possibility that the joint shape varies or the tubular bodies 30 are deformed, so that the gaps 31 become nonuniform is high.

In such a case, a rectangular parallelepiped-shaped magnetic work body 34 having a size of surrounding the hollow ducts 26A to 26D is integrally formed by making two or more of the tubular bodies 30 adjacent to each other and joining so that the center is located at the intersection of a lattice. Then, the tubular bodies 30 on the periphery of the magnetic work body 34 are cut in the axial direction (direction orthogonal to the paper surface) along the inner surface shape of the hollow ducts 26A to 26D indicated by the alternate-long-and-short-dashed-lines as illustrated in FIG. 8A, whereby a magnetic work body 35 having an outer surface shape matched to the inner surface shape of the hollow ducts 26A to 26D is formed as illustrated in FIG. 8B. Then, the magnetic work bodies 35 are accommodated in the hollow ducts 26A to 26D. At this time, the tubular bodies 30 are accommodated in the hollow ducts 26A to 26D with the first magnetic work substance MM1 of each tubular body 30 configuring the magnetic work body 35 as the low temperature end side and the third magnetic work substance MM3 as the high temperature end side.

In this case, only by cutting an outer peripheral portion of the integrated magnetic work body 34 according to the internal shape of the hollow ducts, the magnetic work body 35 matched with the hollow ducts 26A to 26D can be formed. Therefore, deformation or collapse does not occur in a large number of tubular bodies 30 configuring the magnetic work body 35 and the shape of the gap 31 can be accurately maintained without being broken. Therefore, when a heat medium is circulated, a uniform flow can be secured without causing a deviation, so that the heat exchange efficiency can be improved.

Then, high temperature pipes PH11, PH12 are connected to a high temperature end 28 of the hollow duct 26A of the heat pump body 11 having the above-described configuration and high temperature pipes PH21, PH22 are connected to a high temperature end 28 of the hollow duct 26B located at an axisymmetric position to the hollow duct 26A as illustrated in FIG. 1. High temperature pipes PH31, PH32 are connected to a high temperature end 28 of the hollow duct 26C and high temperature pipes PH41, PH42 are connected to a high temperature end 28 of the hollow duct 26D located at an axisymmetric position to the hollow duct 26C.

Similarly, low temperature pipes PL11, PL12 are connected to a low temperature end 29 of the magnetic work body 27A and low temperature pipes PL21, PL22 are connected to a low temperature end 29 of the hollow duct 26B located at an axisymmetric position to the hollow duct 26A. Low temperature pipes PL31, PL32 are connected to a low temperature end 29 of the hollow duct 26C and low temperature pipes PL41, PL42 are connected to a low temperature end 29 of the hollow duct 26D located at an axisymmetric position to the hollow duct 26C.

The high temperature side switching valve 12 contains a rotary valve, an electromagnetic valve, a poppet valve, and the like, for example, and switched and controlled with the rotation of the rotor 21. The high temperature side switching valve 12 is provided with connection ports 12A and 12B connected to the hollow ducts 26A to 26D, an outflow port 12C connected to an inlet of the heat dissipation side heat exchanger 13, and an inflow port 12D connected to a discharge side of the circulating pump 15. The high temperature side switching valve 12 is switched to a state of causing the connection port 12A to communicate with the outflow port 12C synchronizing with the rotation of the rotor 21 described above and causing the connection port 12B to communicate with the inflow port 12D and a state of causing the connection port 12A to communicate with the inflow port 12D and causing the connection port 12B to communicate with the outflow port 12C.

To the connection port 12A, the high temperature pipes PH11 to PH41 drawn out from the heat pump body 11 are connected. To the connection port 12B, the high temperature pipes PH12 to PH42 drawn out from the heat pump body 11 are connected.

The outflow port 12C of the high temperature side switching valve 12 is connected to the inlet of the heat dissipation side heat exchanger 13 through a pipe 41 and an outlet of the heat dissipation side heat exchanger 13 is connected to the suction side of the circulating pump 15 through a pipe 42 and the heater 14 disposed in the middle of the pipe 42. The discharge side of the circulating pump 15 is connected to the inflow port 12D of the high temperature side switching valve 12 through a pipe 43, so that a circulation path on the heat dissipation side is configured.

The low temperature side switching valve 16 contains a rotary valve, an electromagnetic valve, a poppet valve, and the like, for example, and switched and controlled with the rotation of the rotor 21 as with the high temperature side switching valve 12 described above. The low temperature side switching valve 16 is provided with connection ports 16A and 16B connected to the hollow ducts 26A to 26D and an outflow port 16C and an inflow port 16D connected to the heat absorption side heat exchanger 17.

To the connection port 16A, the low temperature pipes PL11 to PL41 drawn out from the heat pump body 11 are connected. To the connection port 16B, the low temperature pipes PL12 to PL42 drawn out from the heat pump body 11 are connected. The outflow port 16C is connected to an inlet of the heat absorption side heat exchanger 17 through a pipe 44 and the inflow port 16D is connected to an outlet of the heat absorption side heat exchanger 17 through a pipe 45, so that a circulation path on the heat absorption side is configured.

Then, the low temperature side switching valve 16 is switched to a state of causing the connection port 16A to communicate with the outflow port 16C synchronizing with the rotation of the rotor 21 described above and causing the connection port 16B to communicate with the inflow port 16D and a state of causing the connection port 16A to communicate with the inflow port 16D and causing the connection port 16B to communicate with the outflow port 12C.

The circulating pump 15, the high temperature side switching valve 12, the low temperature side switching valve 16, and the pipes configure a heat medium moving mechanism of reciprocating a heat medium between the high temperature end 28 and the low temperature end 29 of each of the magnetic work bodies 27A to 27D.

[Operation of Magnetic Heat Pump Device 10]

Next, the operation of the magnetic heat pump device 10 having the above-described configuration is described.

First, when the rotor 21 of the heat pump body 11 is located at a 0° position (position illustrated in FIG. 2), the permanent magnets 25A, 25B are located at 0° and 180° positions. Therefore, the magnitude of magnetic fields applied to the magnetic work bodies 27A, 27B at the 0° and 180° positions increases, so that the magnetic work bodies 27A, 27B are magnetized and the temperature increases.

On the other side, the magnitude of magnetic fields applied to the magnetic work bodies 27C, 27D located at 90° and 270° positions having a phase different therefrom by 90° decreases, so that the magnetic work bodies 27C, 27D are demagnetized and the temperature decreases.

When the rotor 21 is located at the 0° position (FIG. 2), the high temperature side switching valve 12 causes the connection port 12A to communicate with the outflow port 12C and causes the connection port 12B to communicate with the inflow port 12D and the low temperature side switching valve 16 causes the connection port 16A to communicate with the inflow port 16D and causes the connection port 16B to communicate with the outflow port 16C.

By the operation of the circulating pump 15, a heat medium (water) is brought into a state of being circulated as indicated by the solid line arrows in FIG. 1 in the order of the circulating pump 15→the pipe 43→from the inflow port 12D to the connection port 12B of the high temperature side switching valve 12→the high temperature pipes PH32 and PH 42→the magnetic work bodies 27C and 27D at the 90° and 270° positions→the low temperature pipes PL32 and PL42→from the connection port 16B to the outflow port 16C of the low temperature side switching valve 16→the pipe 44→the heat absorption side heat exchanger 17→the pipe 45→from the inflow port 16D to the connection port 16A of the low temperature side switching valve 16→the low temperature pipes PL11 and PL21→the magnetic work bodies 27A and 27B at the 0° and 180° positions→the high temperature pipes PH11 and PH21→from the connection port 12A to the outflow port 12C of the high temperature side switching valve 12→the pipe 41→the heat dissipation side heat exchanger 13→the pipe 42→the heater 14→the circulating pump 15.

The heat medium (water) in the magnetic work bodies 27A, 27B vibrates in the axial direction of the magnetic work bodies 27A, 27B to transmit the heat from the low temperature end 29 to the high temperature end 28, the heat medium (water), the temperature of which has become high at the high temperature end 28, flows out of the high temperature pipes into the heat dissipation side heat exchanger 13 to release the amount of heat corresponding to the work to the outside (open air and the like), and then the heat medium (water), the temperature of which has become low at the low temperature end 29, flows out of the low temperature pipes into the heat absorption side heat exchanger 17 to absorb heat from a body 51 to be cooled to cool the body 51 to be cooled.

More specifically, the heat medium (water) which is cooled by dissipating heat to the magnetic work bodies 27C and 27D, the temperature of which has decreased by being demagnetized, absorbs heat from the body 51 to be cooled in the heat absorption side heat exchanger 17 to cool the body 51 to be cooled. Thereafter, the heat medium (water) absorbs heat from the magnetic work bodies 27A, 27B, the temperature of which has increased by being magnetized, to cool the same, returns to the heat dissipation side heat exchanger 13, and then releases the amount of heat corresponding to the work to the outside (open air and the like).

Next, when the rotor 21 is rotated by 90° with the permanent magnets 25A, 25B, the magnetic work bodies 27A, 27B located at the 0° and 180° positions are demagnetized and the temperature decreases and the magnetic work bodies 27C and 27D located at the 90° and 270° positions are magnetized and the temperature increases. At this time, when the high temperature side switching valve 12 and the low temperature side switching valve 16 contain rotary valves, valve bodies thereof are rotated by 90° with the rotor 21. Therefore, the heat medium (water) is next brought into a state of being circulated as indicated by the dotted line arrows in FIG. 1 in the order of the circulating pump 15→the pipe 43→from the inflow port 12D to the connection port 12B of the high temperature side switching valve 12→the high temperature pipes PH12 and PH22→the magnetic work bodies 27A and 27B at 0° and 180° positions→the low temperature pipes PL12 and PL22→from the connection port 16B to the outflow port 16C of the low temperature side switching valve 16→the pipe 44→the heat absorption side heat exchanger 17→the pipe 45→from the inflow port 16D to the connection port 16A of the low temperature side switching valve 16→the low temperature pipes PL31 and PL41→the magnetic work bodies 27C and 27D at the 90° and 270° positions→the high temperature pipes PH31 and PH41→from the connection port 12A to the outflow port 12C of the high temperature side switching valve 12→the pipe 41→the heat dissipation side heat exchanger 13→the pipe 42→the heater 14→the circulating pump 15.

The rotation of the rotor 21 and the switching of the high temperature side switching valve 12 and the low temperature side switching valve 16 are performed at the number of relatively high speed rotations and relatively high speed timing, the heat medium (water) is reciprocated between the high temperature end 28 and the low temperature end 29 of each of the magnetic work bodies 27A to 27D, and the heat absorption/heat dissipation from each of the magnetic work bodies 27A to 27D to be magnetized/demagnetized is repeated, whereby a temperature difference between the high temperature end 28 and the low temperature end 29 of each of the magnetic work bodies 27A to 27D gradually increases. After a while, the temperature of the low temperature end 29 of each of the magnetic work bodies 27A to 27D connected to the heat absorption side heat exchanger 17 decreases to a temperature at which the refrigerating capacities of the magnetic work bodies 27A to 27D and the heat load of the body 51 to be cooled are balanced, so that the temperature of the high temperature end 28 of each of the magnetic work bodies 27A to 27D connected to the heat dissipation side heat exchanger 13 becomes a substantially constant temperature because the heat dissipation capacity and the refrigerating capacity of the heat dissipation side heat exchanger 13 are balanced.

As described above, when the temperature difference between the high temperature end 28 and the low temperature end 29 of each of the magnetic work bodies 27A to 27D increases by the repetition of the heat absorption/heat dissipation to reach a temperature difference balanced with the capacity of the magnetic work substances, the temperature change is saturated. Herein, FIG. 7 illustrates the temperatures of the high temperature end 28 and the low temperature end 29 in the state where the temperature change is saturated as described above by L21 and L22. As is clarified also from the figure, both the high temperature end 28 and the low temperature end 29 are affected by the heat absorption and the heat dissipation by the magnetization and the demagnetization and the temperature fluctuates with a predetermined temperature width (about 2 K in Examples).

Both or either one of the heat dissipation side heat exchanger 13 and the heat absorption side heat exchanger 17 contains a microchannel heat exchanger in Examples so that heat can be exchanged with the outside (open air or the body 51 to be cooled) with such a small temperature difference. The microchannel heat exchanger has a higher heat transfer coefficient and also a larger heat transfer area per unit volume as compared with those of heat exchangers of the other types, and thus is very suitable for obtaining required capacities by the magnetic heat pump device 10 as in the present invention.

The heat medium supplied to the high temperature end 28 or the low temperature end 29 of each of the magnetic work bodies 27A to 27D flows into the low temperature end 29 side from the high temperature end 28 or into the high temperature end 28 side from the low temperature end 29 through heat medium passages formed of the gaps 31 formed of the outer peripheral surfaces of the adjacent four tubular bodies 30 and the porosity adjusting holes 30 a of the tubular bodies 30. At this time, since both the gap 31 and the porosity adjusting hole 30 a are linearly formed, the flow passage resistance is low and the pressure loss decreases.

Moreover, since the heat medium pas sages contain the gaps 31 and the porosity adjusting holes 30 a of the tubular bodies 30, large porosity can be set and the heat transfer area can be improved by 30% or more as compared with that of a conventional example in which magnetic work substances are filled in the form of spherical particles and can be improved by 50% or more as compared with the conventional example in which a magnetic work substance is formed into a linear body as described in PTL 2. Therefore, good heat exchange can be performed between the magnetic work bodies 27A to 27D and the heat medium.

When the porosities of the magnetic work bodies 27A to 27D are adjusted, the porosity can be easily increased or decreased by changing the inner diameter of the porosity adjusting hole 30 a of the tubular body 30 serving as the single magnetic work body, so that the porosity can be easily adjusted to ideal porosity (for example, around 40%). At this time, it is not necessary to change the outer diameter of the tubular body 30 serving as the single magnetic work body, and therefore the porosity can be adjusted without changing the entire volume of the magnetic work bodies 27A to 27D.

Furthermore, when a block body having a curved surface, such as a cylindrical surface, is formed instead of the rectangular parallelepiped shape as in the magnetic work bodies 27A to 27D, a rectangular parallelepiped capable of covering the block body is formed, and then the outer peripheral surface thereof is cut to form the block body having a desired curved surface, whereby a uniform heat medium passage can be secured without causing deformation of the tubular body 30 and the collapse of the gap, so that a deviation of a heat medium can be certainly prevented.

Second Embodiment

Next, a second embodiment of a magnetic work body according to the present invention is described with FIGS. 9 and 10.

This second embodiment is configured to improve the magnetocaloric effect without changing the flow amount of a heat medium.

More specifically, magnetic work substances 60 are filled into corner portions entering between adjacent two tubular bodies 30 in the gap 31 in the first embodiment described above to form a heat medium flow limited region as illustrated in FIGS. 9 and 10 in the second embodiment.

In the corner portions entering between the adjacent two tubular bodies 30 of the gap 31, the heat medium is difficult to flow due to the surface tension, so that the corner portions do not function as a heat medium passage. Therefore, by filling the regions with the magnetic work substances 60, the entire magnetic work substance amount can be increased without decreasing the heat medium flow amount and the magnetocaloric effect can be improved corresponding to the filling amount of the magnetic work substances 60.

At this time, the magnetic work substances 60 filled into the tip side of the gap 31 can improve the magnetocaloric effect without hindering the flow of a heat medium by filling the same so as to form cylindrical inner surfaces 61 as illustrated in FIG. 10.

The second embodiment described above describes the case where the magnetic work substances 60 are filled into the tip of the gap 31 but is not limited thereto and the gap 31 can be configured also from an integrated extrusion-molded article so as to achieve the gap shape of FIG. 10.

Moreover, the above-described first and second embodiments describe the case where the hollow ducts 26A to 26D in which the magnetic work bodies 27A to 27D are disposed, respectively, are provided in the stator 22 but are not limited thereto and the number of hollow ducts in which the magnetic work bodies are disposed can be set to an arbitrary number and the number of permanent magnets disposed on the rotor 21 can also be arbitrarily set. In short, the number of magnetic work bodies in a magnetized state and the number of magnetic work bodies in a demagnetized state may be equal to each other.

The above-described first and second embodiments describe the case where the tubular body 30 serving as the single magnetic work body contains the three magnetic work substances different in the temperature zone where a high magnetocaloric effect is exhibited but are not limited thereto and the tubular body 30 may contain four or more magnetic work substances.

Moreover, the above-described first and second embodiments describe the case where the adjacent single magnetic work bodies directly contact each other but are not limited thereto and the single magnetic work bodies may be made adjacent to each other with a separate junction member interposed therebetween.

Moreover, the above-described first and second embodiments describe the case where the tubular bodies 30 are joined so that the central axis serves as the intersection of the lattice but are not limited thereto and the tubular bodies 30 may be disposed in zigzag by disposing the central axes of the tubular bodies 30 on even-numbered stages are shifted corresponding to the radius of the tubular body 30 in the horizontal direction with respect to the central axes of the tubular bodies 30 on odd-numbered stages in the vertical direction.

Moreover, the above-described first and second embodiments describe the case where the magnetic heat pump device is configured into an inner rotor type but are not limited thereto and the magnetic heat pump device can also be configured into an outer rotor type.

Furthermore, the heat pump body can be configured as illustrated in FIG. 11. More specifically, a configuration may be acceptable in which magnetic work bodies 70A and 70B formed into a rectangular parallelepiped shape are fixed at the 90° and 270° positions on the circumference sandwiching the rotation shaft 71, rotating disks 72A and 72B fixed to the rotation shaft 71 so as to sandwich the magnetic work bodies 70A to 70D in the vertical direction are disposed, and a pair of permanent magnets 73A and 73B and a pair of permanent magnets 74A and 74B are individually disposed on the facing surfaces at the 0° and 180° positions sandwiching the rotation shaft 71, for example, of the rotating disks 72A and 72B. In this case, the pair of upper permanent magnets 73A and 74A and the pair of lower permanent magnets 73B and 74B generate magnetic fluxes crossing the magnetic work bodies 70A to 70D in the vertical direction by setting the surfaces facing the magnetic work bodies of the permanent magnets 73A and 74A to the N pole (or S pole) and setting the other surfaces facing the magnetic work bodies of the permanent magnets 73B and 74B to the S pole (or N pole).

Moreover, the present invention is not limited to the case of rotating the permanent magnets as the magnetic heat pump device and can also be applied to a reciprocating magnetic heat pump device configured so that a magnetic work body 81 formed into a rectangular parallelepiped shape is fixed and disposed and a linear moving body 83, in which permanent magnets 82A and 82B generating magnetic fluxes crossing the magnetic work body 81 in the vertical direction, for example, are disposed so as to face each other, is linearly reciprocated between a position where the permanent magnets 82A and 82B face the magnetic work body 81 and a position where the permanent magnets 82A and 82B do not face the magnetic work body 81 as illustrated in FIG. 12.

REFERENCE SIGNS LIST

-   -   10 magnetic heat pump device     -   11 heat pump body     -   12 high temperature side switching valve     -   13 heat dissipation side heat exchanger     -   14 heater     -   15 circulating pump     -   16 low temperature side switching valve     -   17 heat absorption side heat exchanger     -   21 rotor     -   22 stator     -   23 rotation shaft     -   24 support member     -   25A, 25B permanent magnet     -   26A to 26D hollow duct     -   27A to 27D magnetic work body     -   30 tubular body     -   30 a porosity adjusting hole     -   31 gap     -   32 square region     -   33 to 35 magnetic work body     -   60 magnetic work substance     -   70A to 70D magnetic work body     -   71 rotation shaft     -   72A, 72B rotating disk     -   73A, 73B, 74A, 74B permanent magnet     -   81 magnetic work body     -   82A, 82B permanent magnet     -   83 linear moving body 

1. A magnetic work body comprising: a tubular body formed of a magnetic work substance and having a porosity adjusting hole in an axial direction configured to adjust porosity when a plurality of rod-shaped bodies are made adjacent to each other and joined inside the rod-shaped body.
 2. A magnetic work body comprising: a plurality of tubular bodies formed of a magnetic work substance and having a porosity adjusting hole in an axial direction configured to adjust porosity when a plurality of rod-shaped bodies are made adjacent to each other and joined inside the rod-shaped body, wherein the tubular bodies are joined in such a manner that cross-sectional shapes of gaps surrounded by the adjacent tubular bodies have a same shape and heat medium passages passing a heat medium are formed with inner surfaces of the tubular bodies and the gaps.
 3. The magnetic work body according to claim 2, wherein the gap is formed to be surrounded by four pieces of the tubular bodies.
 4. The magnetic work body according to claim 3, wherein the tubular bodies are arranged in such a manner that allowable grid lines setting a ±10% allowable level to a standard grid line connecting centers of the four pieces of the tubular bodies are set, and then the center is disposed in a region surrounded by intersections of the allowable grid lines.
 5. The magnetic work body according to claim 3, wherein a corner portion entering between two pieces of the adjacent tubular bodies is a heat medium flow limited region filled with the magnetic work substance in the gap.
 6. The magnetic work body according to claim 1, wherein the tubular body contains an extrusion-molded article of the magnetic work substance.
 7. The magnetic work body according to claim 2, wherein the tubular body is configured by arranging two or more of the magnetic work substances different in a temperature zone where a high magnetocaloric effect is exhibited in the axial direction in such a manner that the temperature zones become high in order.
 8. The magnetic work body according to claim 2, wherein the magnetic work substance is any one of an Mn-based material and an La-based material.
 9. A magnetic heat pump device comprising: ducts which are formed in a cylindrical fixing portion and in which the magnetic work bodies according to claim 2 to are disposed along a heat medium flowing direction; a magnetic field changing mechanism configured to change a magnitude of a magnetic field applied to the magnetic work body of the duct; a heat medium moving mechanism configured to move the heat medium between a high temperature end and a low temperature end of the magnetic work body; a heat dissipation side heat exchanger configured to cause the heat medium on a side of the high temperature end to dissipate heat; and a heat absorption side heat exchanger configured to cause the heat medium on a side of the low temperature end to adsorb heat.
 10. The magnetic heat pump device according to claim 9, wherein the magnetic work body is configured to have a circular arc-shaped cross-section by cutting an outer peripheral portion of a rectangular parallelepiped having a rectangular cross-section formed by joining the plurality of tubular bodies to be matched with a cross-sectional shape of the duct.
 11. The magnetic work body according to claim 4, wherein a corner portion entering between two pieces of the adjacent tubular bodies is a heat medium flow limited region filled with the magnetic work substance in the gap.
 12. The magnetic work body according to claim 11, wherein the tubular body contains an extrusion-molded article of the magnetic work sub stance.
 13. The magnetic work body according to claim 3, wherein the tubular body is configured by arranging two or more of the magnetic work substances different in a temperature zone where a high magnetocaloric effect is exhibited in the axial direction in such a manner that the temperature zones become high in order.
 14. The magnetic work body according to claim 4, wherein the tubular body is configured by arranging two or more of the magnetic work substances different in a temperature zone where a high magnetocaloric effect is exhibited in the axial direction in such a manner that the temperature zones become high in order.
 15. The magnetic work body according to claim 11, wherein the tubular body is configured by arranging two or more of the magnetic work substances different in a temperature zone where a high magnetocaloric effect is exhibited in the axial direction in such a manner that the temperature zones become high in order.
 16. The magnetic work body according to claim 3, wherein the magnetic work substance is any one of an Mn-based material and an La-based material.
 17. The magnetic work body according to claim 4, wherein the magnetic work substance is any one of an Mn-based material and an La-based material.
 18. The magnetic work body according to claim 7, wherein the magnetic work substance is any one of an Mn-based material and an La-based material.
 19. The magnetic work body according to claim 11, wherein the magnetic work substance is any one of an Mn-based material and an La-based material.
 20. A magnetic heat pump device comprising: ducts which are formed in a cylindrical fixing portion and in which the magnetic work bodies according to claim 11 are disposed along a heat medium flowing direction; a magnetic field changing mechanism configured to change a magnitude of a magnetic field applied to the magnetic work body of the duct; a heat medium moving mechanism configured to move the heat medium between a high temperature end and a low temperature end of the magnetic work body; a heat dissipation side heat exchanger configured to cause the heat medium on a side of the high temperature end to dissipate heat; and a heat absorption side heat exchanger configured to cause the heat medium on a side of the low temperature end to adsorb heat. 